1. Technical Field
The present disclosure relates generally to the field of mobile technology and wireless communications. More particularly, in one exemplary embodiment, the present disclosure is directed to resuming radio channel measurements and estimations after an interruption in reception.
2. Description of Related Technology
Wireless networks are based on transmission and reception of Radio Frequency (RF) electro-magnetic waves between at least two devices. During operation, the RF connection will experience a wide range of undesirable effects and attenuations due to e.g., atmospheric effects, intervening obstacles, etc. In some wireless technologies (such as Long Term Evolution (LTE) cellular networks), channel estimation is used by the transmitter or receiver to determine how to compensate for the radio link effects to maximize signal reception. Improving signal reception can greatly improve device performance, reduce data corruption, and reduce processing complexity (and power consumption).
Certain receiver activities can greatly affect channel estimation accuracy. For example, within LTE cellular networks (and certain other advanced wireless networking technologies), the client device may periodically e.g., tune away from the first network (e.g., LTE) to a second network (e.g., CDMA 2000), go to sleep or idle mode and save power when data traffic is low and/or bursty (e.g., Discontinuous Reception (DRX)), perform measurements on other networks or Radio Access Technologies (RATs) (e.g. gap measurements), handover or “camp” onto other networks, and/or experience RF conditions that will lead to interruption of reception. It should be appreciated by those of ordinary skill in the related arts that the radio channel continues to change while the client device is e.g., tuned away or lacks reception; thus, once the client device tunes back, the device will experience a discontinuity (i.e., the channel has shifted in position and power). Existing devices either accept the performance degradation caused by the discontinuity, or determine a new channel estimate from “scratch.”
Consequently, methods and apparatus are needed to improve resumption of radio channel measurements and estimations after an interruption in reception.